A350 heat-soak; when you restart all cooling-systems after been parked in the sun at 48C for several hours.

The Rolls-Royce Trent XWB-powered airframe, MSN3, had headed out to Al Ain late on 11/June, and subsequently carried out a number of test flights over the Persian Gulf.

Airbus said the operation focused on engine behaviour and performance in high-temperature conditions, and checks on systems such as the cooling equipment. The tests included heat-soak, in which the A350 was parked in the sun for several hours.